The present invention relates to acoustic panels, such as ceiling tiles, of the type which have a body of acoustic (i.e. sound absorbing) material and a facing which forms the front face of the panel.
Panels of this type are widely used to provide the visible face of walls or ceilings of rooms or other enclosed spaces such as in offices, factories, domestic homes and public buildings. The panels are mounted as a panel assembly on a grid, for instance by intermeshing of grooves in the edges of the panels with the grid. It is often desirable that the appearance of the wall or ceiling should be created predominantly by a pleasing appearance of the front face of the tiles and should be free of objects which harm its appearance. It is therefore usually desirable that the face of each panel should be flat and it is often desirable that the overall appearance of the wall or ceiling should be as monolithic as possible, that is to say the entire wall or ceiling should appear as flat as possible, with the minimum visibility of joins, in order to simulate the appearance of a conventional plastered wall or ceiling.
It is, however, desirable to locate various devices on or in the surfaces of walls or ceilings. Examples of such devices include lighting units, water sprinklers, sensors for various purposes, surveillance cameras, and loudspeakers. If such devices are fitted on a panel or in a panel they disrupt the appearance of the panel and, if the surface would otherwise be monolithic, they disrupt the appearance of the monolithic surface.
Panel loudspeakers (for instance as described in US 2003/0031331 and EP-A-1,185,134 and typically available commercially under designations such as NXT from the Martin Group in Denmark) can desirably be mounted on a wall or ceiling, but they can then impair the appearance of the wall or ceiling.
EP-A-1,185,134, addresses the problem of providing a panel loudspeaker that can be situated in a ceiling assembly. It proposes replacing an entire ceiling tile from the grid of ceiling tiles with a speaker and covering the speaker with a facing that is visually similar to the surrounding ceiling tiles. This system has the disadvantage that, for any particular ceiling assembly, the loudspeaker needs to be approximately the same size as the ceiling tile which it places. This means that the panel loudspeaker size is dictated by size of the panels in the ceiling or wall into which it is to be filled. Furthermore, a frame must be provided around the loudspeaker to secure the loudspeaker to the grid. Additionally, facing must be provided over the loudspeaker and which must have an appearance that matches the facing of the panels in the assembly.
There exists a need to provide a convenient way of incorporating a speaker of any size (which can therefore be optimised for reasons unrelated to its ultimate position) into an assembly of panels without disrupting the appearance of the ceiling or walls.
Fire protection systems usually comprise a network of sprinklers which extend down from the face of a ceiling and each of which is activated by a temperature sensor. The temperature sensor can be a glass bulb or other device which is part of the sprinkler and which ruptures when the temperature increases so as to actuate the sprinkler, or it can be a separate sensor. A water supply is typically provided above a ceiling assembly and feeds the sprinkler when it is activated. The sprinklers are usually fixed between 20 and 40 mm below the front or visible surface of the ceiling tile and when the temperature sensor senses an increase in temperature indicative of a fire, it will activate the water supply which will be provided through the sprinkler to extinguish the fire.
Water sprinkler systems of this type have the disadvantage that the water sprinklers and temperature sensors are visible from the room, hence disrupting the appearance of the ceiling, and are considered by many people to be unsightly. The exposed water sprinklers are also frequently subjected to vandalism. It is known to mount the sprinkler, when inactive, very close to the ceiling and to arrange for the sprinkler to drop down from the ceiling, by 1 to 5 cm, when activated before water spraying is initiated. However the sprinklers are still clearly visible and disrupt the appearance of the facing of the tiles.
U.S. Pat. No. 3,246,432, addresses the problem of concealing heat sensitive sprinklers in a suspended ceiling by providing a heat softenable ceiling grid and locating the sprinklers above the ceiling tiles which are positioned in the grid. When the temperature rises to a predetermined level, the grid softens and deforms sufficiently to permit the ceiling tiles to drop out of the grid. This exposes the thermosensitive sprinkler heads which then detect the elevated temperature and begin to spray water. In U.S. Pat. No. 4,189,888 the fire sprinklers are mounted above plastic tiles and the sprinklers are exposed only when the tiles are burnt.
Systems such as these are undesirable because of the injury and damage that can be caused by the melting or the burning of the tiles and because of the inevitable delay between the increase in temperature in the room and the initiation of sprinkling. It would therefore be desirable to provide a ceiling assembly which contained sprinklers which did not suffer from these disadvantages.
Sensors, such as intruder alarms, surveillance cameras, lighting and other devices can all desirably be provided but at present they all suffer from the disadvantage that their effectiveness is reduced or destroyed if they are concealed by the panel, but the appearance of the ceiling or wall is harmed if they are not concealed by the panel.